I've played quite a lot of games with the new list over the last two months and I'm really happy with it. 75% wins against eldar and the imperial guard. Usually we play for 3500pts per match and I have about 11-12 activations per list.
I noticed two things:
1. The list needs an Assault Marines upgrade, sth like Raptors but without the jump packs. Can we add them to the list? how about as a core formation but no more than 1 per Iron warriors detachment. Or as an upgrade. this will increase variety and gives the IW some shock troops for that beach in the wall

I just don't know how to cost them...
2.The Iron Warriors detachment shouldn't be able to buy more than one infantry upgrade. For 300pts you have a lord, 6 CSM and 2 Havocs, add a Havoc upgrade (150pts)and 4 extra CSM units (140pts). You have a company for 590pts made up of 16 marine units, with a leader and 24 autocannon shots. Seems a little too much and it's extremely hard to eradicate for the opponent and they will probably hold that blitzkrieg for you no matter what happens.
How about we change it so that only 1 infantry upgrade is possible? Only CSM/or Havocs? or Assault Marines?. This way you won't be able to make the companies so huuuge. I know someone might say you throw in all your eggs into one basket, but still it does it's job.
Otherwise I think the list is very solid and with the above changes I would consider it finished.
Cheers, Laylo